Modification of Cellulose Nanocrystals as Antibacterial Nanofillers to Fabricate Rechargeable Nanocomposite Films for Active Packaging

Abstract

Growing food safety concerns have required the development of functional films incorporated with antibacterial nanofillers for active packaging, and cellulose nanocrystals (CNCs) are promising candidates due to their unique morphology and availability for modification. Herein, this study aims to develop an approach to producing functional CNCs that can be easily incorporated into commercial plastic films as antibacterial nanofillers for active packaging. Particularly, CNCs extracted from cotton textile waste were selected as a model and modified with methacrylamide (MAM). Cellulose acetate (CA) and poly(vinyl chloride) (PVC) were chosen as film-forming agents, and the modified CNCs (MAM-CNCs) were incorporated by the solution casting method. Addition of MAM-CNCs significantly improved the mechanical and UV barrier properties of CA and PVC films. After chlorination, the composite films with 3% MAM-CNCs exhibited excellent antibacterial efficacy against common foodborne pathogens, e.g., higher than 6 log reduction of Staphylococcus aureus and Escherichia coli after 1 h of contact at 37 °C. Moreover, this antibacterial capacity could be recharged by chlorination without affecting the mechanical performance of plastic films. Therefore, this work reveals the potential of utilizing modified CNCs to fabricate functional packaging materials.